The bears may be gone, but their old cages can still be found.

This railroad tunnel was once the longest in Massachusetts.

Site of a famous 19th-century transcendentalist utopian community, now abandoned.

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

This dam in the woods, built by Henry Ford with only manpower and oxen, holds no water and serves no purpose.

Once the largest public hospital for the mentally ill was also surrounded by controversy.

Accessible only by boat, this centuries-old island fort never saw troops or combat.

The only surviving building of historic West Boylston, which was flooded to create the Wachusett Reservoir.

Instead of becoming a power plant, this abandoned complex became a massive letdown.

Hidden amid a collection of trails is the site of a tragic crash.

The remains of the iconic train crash from the movie The Fugitive can still be found rusting along the Great Smoky Railroad.

The remains of one of America's first radiation testing grounds still rest ominously in a Georgia forest.

All that's left of the quintessential "cabin in the woods."

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

The first KFC is on the National Register of Historic Places.

An abandoned railroad tunnel forgotten by time awaits inquisitive hikers.

The scant remains of this flooded historic village can be explored in one of the most remote areas of the Great Smokies.

This 19th-century building inadvertently preserved the handprints of its builders within its walls.

One of the world's largest automobile junkyards is a unique landscape of metal and moss.

World's largest college campus includes a wildlife sanctuary and a former movie set on more than 28,000 acres.

Abandoned for 60 years, this submerged bridge was completely forgotten until the lake was drained.

One man’s religious convictions led him to build this stone castle meant to withstand an apocalypse.

One man has spent decades faithfully constructing this unique brick and cinderblock castle.

John Hendrix predicted the creation of the "Secret City" built as part of the Manhattan Project.